1. Field of the Invention
The present invention relates to athletic training footwear that specifically enhances running speed, vertical jump, pedal quickness, and pedal balance. In the preferred embodiment of the present invention, synthetic sand is used as the sand simulating material at each of the user's feet, and therefore, simulates the positive effects of beach training (exercising in deep sand). Although it is not a primary objective of the present invention to provide a cushioning effect to the user's feet and related joints, a shock-absorbing effect does, in fact, naturally result. The invention is therefore indirectly related to the field of pedal cushioning which includes therapeutic footwear, and footwear inserts. The present invention utilizes an improved sand simulating material at a specific depth and position under the user's foot for the primary purpose of strengthening the muscles of the lower leg and foot that control plantar flexion of the foot (push-off) and more specifically, the flexion (push-off) of the toes.
2. Description of the Related Art
Because two separate fields of the invention are encountered-recreational/athletic footwear/devices and therapeutic footwear/inserts, related prior art exists from both fields. Several patents exist from the field of recreational footwear. Braun (DT 2,435,094) discloses a pedal attachment comprising an upper platform, and a flat sole wherein steel springs or plastic and foam create a spring effect for recreational walking or jumping. Gluecksmann (U.S. Pat. No. 337,146) discloses a recreational spring shoe that is contained by a continuous wall beneath the user's feet. Lekhtman (U.S. Pat. No. 5,205,798) discloses footwear that comprises a detachable arched spring member that has safety features. In Braun, Gluecksmann, Lekhtman, and related art, the primary goal is to add spring or bounce to each step where the user's entire foot, heel to toe, is supported and affected. In each case the desired effect is to facilitate running and jumping by adding to the equal and opposite force that standard ground contact provides. Standard ground contact is provided by such surfaces as hard earth, gym floor, track surfaces, pavement, etc. In contrast, it is the primary goal the present invention is to specifically decrease the equal and opposite force that standard ground contact provides for the purpose of intensified athletic training by simulating beach training (exercising in deep sand).
Two patents are related from the field of athletic training footwear and/or devices. Cox (U.S. Pat. No. 3,739,500) discloses a shoe that supports only the front of the user's foot for use in athletic training. Kim (U.S. Pat. No. 5,461,799) discloses an attachment to the front of the user's existing footwear for the same purpose. In both cases, the platform element is a firm structure that elevates the foot while providing an equal and opposite ground-contacting force through that structure. In fact, Kim describes the platform element as being, " . . . a firm, resilient material, which is resistant to compression . . . " (U.S. Pat. No. 5,461,799). Where both Cox and Kim maintain an equal and opposite ground contact through the use of `firm, resilient` platform elements, the present invention decreases the equal and opposite force that standard ground contact provides through the use of a contained sand simulating material as the pillar element. The result is intensified overall athletic training and a broader range of motion in strengthening the muscles of the lower legs and feet.
Several patents exist in the indirectly related field of pedal cushioning in the form of therapeutic footwear, and footwear inserts. Ganter (U.S. Pat. No. 4,697,361) discloses a shock-absorbing shoe insert that utilizes sand in thin, strategically placed chambers along the user's entire foot. Meyers (U.S. Pat. No. 4,297,797) discloses a therapeutic shoe that comprises sand and air beneath the user's entire foot. Bos (U.S. Pat. No. 4,955,147) discloses a shoe having a flat inner surface comprising, `highly springy elastic material` to achieve the desired effects afforded by the shoe. Moss (U.S. Pat. No. 4,170,078) discloses a sole for a shoe that is ergonomically designed for the entire foot that utilizes chambers of loose sand beneath the surface. In Ganter, Meyers, Bos, Moss, and related prior art including those that utilize gels, liquids, air, sand, and other materials, the primay focus is foot comfort and therapeutic value where the entire foot is met with cushioning support. Because it is the primary focus of the present invention to provide the user with an intensified athletic workout, only the front of the user's foot corresponding to the ball of the foot and forward including the toes is supported by a substantial depth of sand simulating material (2"-3"). The heel is left unsupported so that the muscles of the lower leg and foot are automatically employed to support the user's bodyweight. Because the primary focus of the present invention is to intensify athletic training as opposed to create therapeutic value, it takes a novel form and utilizes an improved material in the preferred embodiment for that purpose.